Propeller unit



Juhe 15, 1937. BAUMANN E AL 2,083,771

PROPELLER UNI T Filed NOV. 5, 1934 2 Sheets-Sheet 1 June 15, 1937.BAUMANN ET AL 2,083,771

PROPELLER UNIT Filed Nov. 5, 1954 2 Sheets-Sheet 2 Patented June 15,1937 PATENT OFFICE PROPELLER UNIT Louis P. Baumann and Lesley L. Walker,Houston, Tex.

Application November 5, 1934, Serial No. 751,565

1 Claim.

This invention relates to a propeller unit for out-board motors, and hasparticular relation to the lower unit carrying the propeller on outboardmotors designed for use on water craft. 5 An object of the invention isto provide in an out-board motor unit a novel type and a novelarrangement of the propeller.

Another object of the invention is to provide a novel type of gear case.

A further object of the invention is to provide a propeller arranged infront of the lower unit to I the end that the propeller will work inquiet water in front of the gear case rather than in disturbed water, aswould be the case if the pro- AJ peller were located behind the gearcase.

A still further object of the invention is to provide a propeller whoseblades are of maximum width at the hub or central portion of thepropeller, and gradually taper off toward the tips or 20 ends of thepropeller blades.

A further object of the invention is to provide a propeller havingblades Whose forward margins are formed with sharp cutting edges and areof such spiral formation that said edges will out, or

25 slice, the water at approximately right angles to the line of travelof the propeller, the rear margin of the propeller being shaped tooperate in a plane approximately vertical to said line of travel, all tothe end that the propellerwill cause a min- 30 irnum of disturbance, orchurning of the water through which it passes and with the result that amaximum traction effect will be obtained.

A still further object of the invention is to provide a pinion shafthousing and gear case of 35 novel external contour which is effective toreduce the friction of the gear case against the water, said externalcontour being such that substantially no vacuum will be created in thewater behind'the gear case as the craft moves forward.

With the above and other objects in view, the invention has particularrelation to certain novel features of construction, operation, andarrangement of parts, an example of which is given in thisspecification, and illustrated in the accompanying drawings, wherein:-

Figure 1 shows a fragmentary side view of a water craft showing anout-board motor attached embodying the novel form of lower unit 50herein described.

Figure 2 shows a rear elevation of the lower unit.

Figure 3 shows a side view thereof.

Figure 4 shows a cross-sectional View taken on 55 the line 44 of Figure3.

Figure 5 shows afront elevation of the propeller, and

Figure 6 shows a vertical sectional view taken on the line 6--6 ofFigure 3.

In the drawings, the numeral l designates a water craft having theout-board motor 2, of conventional construction, secured thereto in theusual way. This motor has the usual depending housing 3 for the driveshaft and secured to the lower end of this housing 3 is the pinion shafthousing 4 whose lower end is formed into the upper half of the gear case5.

In the pinion shaft housing there is the vertical pinion shaft 6 whichis mounted to rotate in the upper and lower bearings I, la.

The lower end of the shaft 6 has the beveled pinion 8 fixed thereonwhich is in mesh with a corresponding pinion 9 which is fixed on thepropeller shaft ID. This shaft is mounted in suitable bearings II, II,said pinions 8 and 9, the

shaft l and the bearings ll all being enclosed within gear case 5.

Fixed on the forward end of the shaft H there is 'a propeller, indicatedgenerally by the numeral l2. The propeller has the blades 'l3, 13, whosemaximum width is at the hub of the propeller and which taper outwardlytoward their ends or tips. The forward margins of the blades are curvedand terminate in sharp cutting edges. The said forward margins are socurved with respect to each other as to present a reverse curve from tipto tip of the propeller, and the blades are so pitched that said cuttingedges will cut, or slice, the water in a plane substantially at rightangles to the line of travel of the craft to the end that a maximumtraction effect will be obtained without undue dissipation of power inchurning or disturbing the water in front of the propeller. The rearmargin of the propeller, from tip to tip, lies in a plane approximatelyvertical to the line of travel of the craft so that said rear, ortrailing margin, of the propeller will move through the water with aminimum of resistance.

The gear case has a depending fin I4 extending fore and aft, which actswith a stabilizing effect. It will be noted that the pinion shafthousing t, as Well as the gear case 5, are slightly flared rearwardly,the flared portions having slightly convex sides so as to move throughthe water with a minimum of friction. The rear portions of the pinionshaft housing and gear case are reduced in thickness forming the reducedportions 4a and 5a and forming also the abrupt vertical shoulders l5,l6.

As the craft moves through the water, the forward convex sides of thehousing 4 and gear case 5 only will come into frictional contact withthe water and the water will be thrown outwardly each way thereby sothat there will be no frictional contact of the water against thereduced portions 40., 5a, and no vacuum will be formed with retardingefiect behind the pinion shaft housing and gear case.

The drawings and description disclose what is now considered to be apreferred form of the invention by way of illustration only, while thebroad principle of the invention will be defined by the appended claim.

What we claim is:

A propeller unit comprising a housing whose lower end is formed into anapproximately cylindrical gear case which has a blunt trailing end, thehousing extending upwardly from the gear case and having attaching meansat its upper end for attaching the same to a driving means, saidupwardly extending portion being relatively thin and having a forwardlydirected sharp cutting edge and having substantially flat sides whichradiate rearwardlyfrom said edge and are offset inwardly atapproximately right angles to the longitudinal central line of thehousing thus reducing the transverse diameter of the upwardly extendedportion of the housing, said reduced portion being extended rearwardlywith its sides approximately parallel to each other and to said centralline of the housing, the trailing or rear edge of said reduced portionbeing blunt and arranged at substantially right angles to said centralline, the rear end of the gear case being also offset inwardly atapproximately right angles to the line of movement of the housing thusreducing the transverse diameter of the gear case, the points ofreduction of the upwardly extended portion of the housing being inapproximate alignment with the point of reduction of the gear case, adepending fin like stabilizer arranged in a common plane with saidcentral line and being approximately triangular in cross-sectionalcontour and projecting rearwardly beyond the blunt 20 edge of thehousing.

LESLEY L. WALKER. LOUIS P. BAUMANN.

